Auth0.swift v3 Migration

Migrates an existing Auth0.swift v2 integration to v3. Every code change is gated on a search that confirms the project actually calls the affected API — if the project never uses CredentialsManager, no CredentialsManager code is touched. Changes follow the project's existing architecture and Apple platform conventions.

When NOT to Use

• New Auth0 integration (no existing Auth0.swift): Use auth0-swift
• Minor/patch update (e.g., 2.17 → 2.18): Run pod update Auth0 or update SPM — no migration needed
• Android apps: Use auth0-android
• React Native / Expo: Use auth0-react-native or auth0-expo

Prerequisites

• Existing Auth0.swift v2 integration
• Xcode installed; project builds cleanly on the current version
• Project under git version control with a clean working tree